Điểm nổi bật của học thuyết Z

The school cafeteria can make pizza for approximately $0.30 a slice. the cost of kitchen use and cafeteria staff runs about $200 per day. the pizza den nearby will deliver whole pizzas for $9.00 each. the cafeteria staff cuts the pizza into eight slices and serves them in the usual cafeteria line. with no cooking duties, the staff can be reduced by half, for a fixed cost of $75 per day. should the school cafeteria make or buy its pizzas?